From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 938C3C4332F for ; Tue, 22 Nov 2022 03:12:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232197AbiKVDMv (ORCPT ); Mon, 21 Nov 2022 22:12:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35642 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232202AbiKVDMs (ORCPT ); Mon, 21 Nov 2022 22:12:48 -0500 Received: from mail-wr1-x434.google.com (mail-wr1-x434.google.com [IPv6:2a00:1450:4864:20::434]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A3F695F48; Mon, 21 Nov 2022 19:12:44 -0800 (PST) Received: by mail-wr1-x434.google.com with SMTP id s5so5552752wru.1; Mon, 21 Nov 2022 19:12:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=VUB96Tl9URc8ykUeRE0U9dBbBI1ZMs5M2rQ4lm59+vg=; b=Ke2uGmHR2Kmz3bZmTD/IwudMbCM2Xa4JtHmaEtdqBIx52QuGTyGZmGngmZRei+xf2X WuStjbJgJEYQeMPyLyMLaIwDcsTt6wTJtcBcyLfM0CwMRaMvXmCcJgbGgMcvk2HC8qQG h72aqV9GwYO7sAFsGojN/8KXXV9u4ZYxAu39nj2vzuidNB0IPaVODKamW/SPEvzLW5st v7NQA+D0dpjEwV7Ul523TVLpsdPjTzM3ueDrLS0ugsu1YmHl7CaizY+5NiXCU9raAEQ5 vZoeUiw6bkTe2yM9aAHZ9JGt4NqjS8fgLiDGeFiTHLk3LRRkwMdmr8yUIbQ5RqHNGLI5 oyEQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=VUB96Tl9URc8ykUeRE0U9dBbBI1ZMs5M2rQ4lm59+vg=; b=sh0d5FUvIAh9YKLiiPXX+OTxWunZWJ2cBy6xEnYXg07c8xeO8QEhyS/YqqS12vHa1C IKWpgCnD3w0CqE+nWQ1PXzwF1SDc1tK/1EZCiiau3VXDCDkwt6vC9hIhs3Unt+Q3ZGsZ D0gQ6Mc+/aNSveS6wfBWRETnT9plfelk7wakCaJiu39PdpUlzuIm/engCmhTJZU3zMWF MHvXByX0EQO04WzPo/nu1sFVYXd7D31F0h+ui3qh+W0SpH+IwTMhE1EAZguo5CHITERz 88cBrx+lksfC/Lk8PzXw981arRCAqc8MAerBH3AOfjgW6YRSYOCUV/f06w41V0rb0Zno Cpug== X-Gm-Message-State: ANoB5pnk3+kgHFqtbxRdzITNBNoApfmau1zgWZorBxblmvS8HOmRkcwl g3sJ0mDssws3bZkbP2pQmq3jtFZrKNK68Y4+gmo= X-Google-Smtp-Source: AA0mqf7TA8yMkkJs9XxCGWko1bb7/TGc6TZvX9/UYaIDMrVgy8XFbtM9lyHeNLoMEv0yJ9dQsSncm+k+PlaUyNQh8f0= X-Received: by 2002:adf:d231:0:b0:241:e2d1:ec92 with SMTP id k17-20020adfd231000000b00241e2d1ec92mr452609wrh.408.1669086762474; Mon, 21 Nov 2022 19:12:42 -0800 (PST) MIME-Version: 1.0 References: <20221121100521.56601-1-xiangxia.m.yue@gmail.com> <20221121100521.56601-2-xiangxia.m.yue@gmail.com> <7ed2f531-79a3-61fe-f1c2-b004b752c3f7@huawei.com> In-Reply-To: <7ed2f531-79a3-61fe-f1c2-b004b752c3f7@huawei.com> From: Tonghao Zhang Date: Tue, 22 Nov 2022 11:12:04 +0800 Message-ID: Subject: Re: [net-next] bpf: avoid hashtab deadlock with try_lock To: Hou Tao Cc: netdev@vger.kernel.org, Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , bpf Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org . On Tue, Nov 22, 2022 at 9:16 AM Hou Tao wrote: > > Hi, > > On 11/21/2022 6:05 PM, xiangxia.m.yue@gmail.com wrote: > > From: Tonghao Zhang > > > > The commit 20b6cc34ea74 ("bpf: Avoid hashtab deadlock with map_locked"), > > try to fix deadlock, but in some case, the deadlock occurs: > > > > * CPUn in task context with K1, and taking lock. > > * CPUn interrupted by NMI context, with K2. > > * They are using the same bucket, but different map_locked. > It is possible when n_buckets is less than HASHTAB_MAP_LOCK_COUNT (e.g., > n_bucket=4). If using hash & min(HASHTAB_MAP_LOCK_MASK, n_bucket - 1) as the > index of map_locked, I think the deadlock will be gone. Yes, but for saving memory, HASHTAB_MAP_LOCK_MASK should not be too large(now this value is 8-1). if user define n_bucket ,e.g 8192, the part of bucket only are selected via hash & min(HASHTAB_MAP_LOCK_MASK, n_bucket - 1). > > | Task > > | > > +---v----+ > > | CPUn | > > +---^----+ > > > > | NMI > > > > Anyway, the lockdep still warn: > > [ 36.092222] ================================ > > [ 36.092230] WARNING: inconsistent lock state > > [ 36.092234] 6.1.0-rc5+ #81 Tainted: G E > > [ 36.092236] -------------------------------- > > [ 36.092237] inconsistent {INITIAL USE} -> {IN-NMI} usage. > > [ 36.092238] perf/1515 [HC1[1]:SC0[0]:HE0:SE1] takes: > > [ 36.092242] ffff888341acd1a0 (&htab->lockdep_key){....}-{2:2}, at: htab_lock_bucket+0x4d/0x58 > > [ 36.092253] {INITIAL USE} state was registered at: > > [ 36.092255] mark_usage+0x1d/0x11d > > [ 36.092262] __lock_acquire+0x3c9/0x6ed > > [ 36.092266] lock_acquire+0x23d/0x29a > > [ 36.092270] _raw_spin_lock_irqsave+0x43/0x7f > > [ 36.092274] htab_lock_bucket+0x4d/0x58 > > [ 36.092276] htab_map_delete_elem+0x82/0xfb > > [ 36.092278] map_delete_elem+0x156/0x1ac > > [ 36.092282] __sys_bpf+0x138/0xb71 > > [ 36.092285] __do_sys_bpf+0xd/0x15 > > [ 36.092288] do_syscall_64+0x6d/0x84 > > [ 36.092291] entry_SYSCALL_64_after_hwframe+0x63/0xcd > > [ 36.092295] irq event stamp: 120346 > > [ 36.092296] hardirqs last enabled at (120345): [] _raw_spin_unlock_irq+0x24/0x39 > > [ 36.092299] hardirqs last disabled at (120346): [] generic_exec_single+0x40/0xb9 > > [ 36.092303] softirqs last enabled at (120268): [] __do_softirq+0x347/0x387 > > [ 36.092307] softirqs last disabled at (120133): [] __irq_exit_rcu+0x67/0xc6 > > [ 36.092311] > > [ 36.092311] other info that might help us debug this: > > [ 36.092312] Possible unsafe locking scenario: > > [ 36.092312] > > [ 36.092313] CPU0 > > [ 36.092313] ---- > > [ 36.092314] lock(&htab->lockdep_key); > > [ 36.092315] > > [ 36.092316] lock(&htab->lockdep_key); > > [ 36.092318] > > [ 36.092318] *** DEADLOCK *** > > [ 36.092318] > > [ 36.092318] 3 locks held by perf/1515: > > [ 36.092320] #0: ffff8881b9805cc0 (&cpuctx_mutex){+.+.}-{4:4}, at: perf_event_ctx_lock_nested+0x8e/0xba > > [ 36.092327] #1: ffff8881075ecc20 (&event->child_mutex){+.+.}-{4:4}, at: perf_event_for_each_child+0x35/0x76 > > [ 36.092332] #2: ffff8881b9805c20 (&cpuctx_lock){-.-.}-{2:2}, at: perf_ctx_lock+0x12/0x27 > > [ 36.092339] > > [ 36.092339] stack backtrace: > > [ 36.092341] CPU: 0 PID: 1515 Comm: perf Tainted: G E 6.1.0-rc5+ #81 > > [ 36.092344] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 > > [ 36.092349] Call Trace: > > [ 36.092351] > > [ 36.092354] dump_stack_lvl+0x57/0x81 > > [ 36.092359] lock_acquire+0x1f4/0x29a > > [ 36.092363] ? handle_pmi_common+0x13f/0x1f0 > > [ 36.092366] ? htab_lock_bucket+0x4d/0x58 > > [ 36.092371] _raw_spin_lock_irqsave+0x43/0x7f > > [ 36.092374] ? htab_lock_bucket+0x4d/0x58 > > [ 36.092377] htab_lock_bucket+0x4d/0x58 > > [ 36.092379] htab_map_update_elem+0x11e/0x220 > > [ 36.092386] bpf_prog_f3a535ca81a8128a_bpf_prog2+0x3e/0x42 > > [ 36.092392] trace_call_bpf+0x177/0x215 > > [ 36.092398] perf_trace_run_bpf_submit+0x52/0xaa > > [ 36.092403] ? x86_pmu_stop+0x97/0x97 > > [ 36.092407] perf_trace_nmi_handler+0xb7/0xe0 > > [ 36.092415] nmi_handle+0x116/0x254 > > [ 36.092418] ? x86_pmu_stop+0x97/0x97 > > [ 36.092423] default_do_nmi+0x3d/0xf6 > > [ 36.092428] exc_nmi+0xa1/0x109 > > [ 36.092432] end_repeat_nmi+0x16/0x67 > > [ 36.092436] RIP: 0010:wrmsrl+0xd/0x1b > > [ 36.092441] Code: 04 01 00 00 c6 84 07 48 01 00 00 01 5b e9 46 15 80 00 5b c3 cc cc cc cc c3 cc cc cc cc 48 89 f2 89 f9 89 f0 48 c1 ea 20 0f 30 <66> 90 c3 cc cc cc cc 31 d2 e9 2f 04 49 00 0f 1f 44 00 00 40 0f6 > > [ 36.092443] RSP: 0018:ffffc900043dfc48 EFLAGS: 00000002 > > [ 36.092445] RAX: 000000000000000f RBX: ffff8881b96153e0 RCX: 000000000000038f > > [ 36.092447] RDX: 0000000000000007 RSI: 000000070000000f RDI: 000000000000038f > > [ 36.092449] RBP: 000000070000000f R08: ffffffffffffffff R09: ffff8881053bdaa8 > > [ 36.092451] R10: ffff8881b9805d40 R11: 0000000000000005 R12: ffff8881b9805c00 > > [ 36.092452] R13: 0000000000000000 R14: 0000000000000000 R15: ffff8881075ec970 > > [ 36.092460] ? wrmsrl+0xd/0x1b > > [ 36.092465] ? wrmsrl+0xd/0x1b > > [ 36.092469] > > [ 36.092469] > > [ 36.092470] __intel_pmu_enable_all.constprop.0+0x7c/0xaf > > [ 36.092475] event_function+0xb6/0xd3 > > [ 36.092478] ? cpu_to_node+0x1a/0x1a > > [ 36.092482] ? cpu_to_node+0x1a/0x1a > > [ 36.092485] remote_function+0x1e/0x4c > > [ 36.092489] generic_exec_single+0x48/0xb9 > > [ 36.092492] ? __lock_acquire+0x666/0x6ed > > [ 36.092497] smp_call_function_single+0xbf/0x106 > > [ 36.092499] ? cpu_to_node+0x1a/0x1a > > [ 36.092504] ? kvm_sched_clock_read+0x5/0x11 > > [ 36.092508] ? __perf_event_task_sched_in+0x13d/0x13d > > [ 36.092513] cpu_function_call+0x47/0x69 > > [ 36.092516] ? perf_event_update_time+0x52/0x52 > > [ 36.092519] event_function_call+0x89/0x117 > > [ 36.092521] ? __perf_event_task_sched_in+0x13d/0x13d > > [ 36.092526] ? _perf_event_disable+0x4a/0x4a > > [ 36.092528] perf_event_for_each_child+0x3d/0x76 > > [ 36.092532] ? _perf_event_disable+0x4a/0x4a > > [ 36.092533] _perf_ioctl+0x564/0x590 > > [ 36.092537] ? __lock_release+0xd5/0x1b0 > > [ 36.092543] ? perf_event_ctx_lock_nested+0x8e/0xba > > [ 36.092547] perf_ioctl+0x42/0x5f > > [ 36.092551] vfs_ioctl+0x1e/0x2f > > [ 36.092554] __do_sys_ioctl+0x66/0x89 > > [ 36.092559] do_syscall_64+0x6d/0x84 > > [ 36.092563] entry_SYSCALL_64_after_hwframe+0x63/0xcd > > [ 36.092566] RIP: 0033:0x7fe7110f362b > > [ 36.092569] Code: 0f 1e fa 48 8b 05 5d b8 2c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 2d b8 2c 00 f7 d8 64 89 018 > > [ 36.092570] RSP: 002b:00007ffebb8e4b08 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 > > [ 36.092573] RAX: ffffffffffffffda RBX: 0000000000002400 RCX: 00007fe7110f362b > > [ 36.092575] RDX: 0000000000000000 RSI: 0000000000002400 RDI: 0000000000000013 > > [ 36.092576] RBP: 00007ffebb8e4b40 R08: 0000000000000001 R09: 000055c1db4a5b40 > > [ 36.092577] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 > > [ 36.092579] R13: 000055c1db3b2a30 R14: 0000000000000000 R15: 0000000000000000 > > [ 36.092586] > > > > Cc: Alexei Starovoitov > > Cc: Daniel Borkmann > > Cc: Andrii Nakryiko > > Cc: Martin KaFai Lau > > Cc: Song Liu > > Cc: Yonghong Song > > Cc: John Fastabend > > Cc: KP Singh > > Cc: Stanislav Fomichev > > Cc: Hao Luo > > Cc: Jiri Olsa > > Signed-off-by: Tonghao Zhang > > --- > > kernel/bpf/hashtab.c | 96 +++++++++++++++++--------------------------- > > 1 file changed, 36 insertions(+), 60 deletions(-) > > > > diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c > > index 22855d6ff6d3..429acd97c869 100644 > > --- a/kernel/bpf/hashtab.c > > +++ b/kernel/bpf/hashtab.c > > @@ -80,9 +80,6 @@ struct bucket { > > raw_spinlock_t raw_lock; > > }; > > > > -#define HASHTAB_MAP_LOCK_COUNT 8 > > -#define HASHTAB_MAP_LOCK_MASK (HASHTAB_MAP_LOCK_COUNT - 1) > > - > > struct bpf_htab { > > struct bpf_map map; > > struct bpf_mem_alloc ma; > > @@ -104,7 +101,6 @@ struct bpf_htab { > > u32 elem_size; /* size of each element in bytes */ > > u32 hashrnd; > > struct lock_class_key lockdep_key; > > - int __percpu *map_locked[HASHTAB_MAP_LOCK_COUNT]; > > }; > > > > /* each htab element is struct htab_elem + key + value */ > > @@ -146,35 +142,26 @@ static void htab_init_buckets(struct bpf_htab *htab) > > } > > } > > > > -static inline int htab_lock_bucket(const struct bpf_htab *htab, > > - struct bucket *b, u32 hash, > > +static inline int htab_lock_bucket(struct bucket *b, > > unsigned long *pflags) > > { > > unsigned long flags; > > > > - hash = hash & HASHTAB_MAP_LOCK_MASK; > > - > > - preempt_disable(); > > - if (unlikely(__this_cpu_inc_return(*(htab->map_locked[hash])) != 1)) { > > - __this_cpu_dec(*(htab->map_locked[hash])); > > - preempt_enable(); > > - return -EBUSY; > > + if (in_nmi()) { > > + if (!raw_spin_trylock_irqsave(&b->raw_lock, flags)) > > + return -EBUSY; > > + } else { > > + raw_spin_lock_irqsave(&b->raw_lock, flags); > > } > > > > - raw_spin_lock_irqsave(&b->raw_lock, flags); > > *pflags = flags; > > - > > return 0; > > } > map_locked is also used to prevent the re-entrance of htab_lock_bucket() on the > same CPU, so only check in_nmi() is not enough. NMI, IRQ, and preempt may interrupt the task context. In htab_lock_bucket, raw_spin_lock_irqsave disable the preempt and irq. so only NMI may interrupt the codes, right ? > > -static inline void htab_unlock_bucket(const struct bpf_htab *htab, > > - struct bucket *b, u32 hash, > > +static inline void htab_unlock_bucket(struct bucket *b, > > unsigned long flags) > > { > > - hash = hash & HASHTAB_MAP_LOCK_MASK; > > raw_spin_unlock_irqrestore(&b->raw_lock, flags); > > - __this_cpu_dec(*(htab->map_locked[hash])); > > - preempt_enable(); > > } > > > > static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node); > > @@ -467,7 +454,7 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr) > > bool percpu_lru = (attr->map_flags & BPF_F_NO_COMMON_LRU); > > bool prealloc = !(attr->map_flags & BPF_F_NO_PREALLOC); > > struct bpf_htab *htab; > > - int err, i; > > + int err; > > > > htab = bpf_map_area_alloc(sizeof(*htab), NUMA_NO_NODE); > > if (!htab) > > @@ -513,15 +500,6 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr) > > if (!htab->buckets) > > goto free_htab; > > > > - for (i = 0; i < HASHTAB_MAP_LOCK_COUNT; i++) { > > - htab->map_locked[i] = bpf_map_alloc_percpu(&htab->map, > > - sizeof(int), > > - sizeof(int), > > - GFP_USER); > > - if (!htab->map_locked[i]) > > - goto free_map_locked; > > - } > > - > > if (htab->map.map_flags & BPF_F_ZERO_SEED) > > htab->hashrnd = 0; > > else > > @@ -549,13 +527,13 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr) > > if (htab->use_percpu_counter) { > > err = percpu_counter_init(&htab->pcount, 0, GFP_KERNEL); > > if (err) > > - goto free_map_locked; > > + goto free_buckets; > > } > > > > if (prealloc) { > > err = prealloc_init(htab); > > if (err) > > - goto free_map_locked; > > + goto free_buckets; > > > > if (!percpu && !lru) { > > /* lru itself can remove the least used element, so > > @@ -568,12 +546,12 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr) > > } else { > > err = bpf_mem_alloc_init(&htab->ma, htab->elem_size, false); > > if (err) > > - goto free_map_locked; > > + goto free_buckets; > > if (percpu) { > > err = bpf_mem_alloc_init(&htab->pcpu_ma, > > round_up(htab->map.value_size, 8), true); > > if (err) > > - goto free_map_locked; > > + goto free_buckets; > > } > > } > > > > @@ -581,11 +559,10 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr) > > > > free_prealloc: > > prealloc_destroy(htab); > > -free_map_locked: > > +free_buckets: > > if (htab->use_percpu_counter) > > percpu_counter_destroy(&htab->pcount); > > - for (i = 0; i < HASHTAB_MAP_LOCK_COUNT; i++) > > - free_percpu(htab->map_locked[i]); > > + > > bpf_map_area_free(htab->buckets); > > bpf_mem_alloc_destroy(&htab->pcpu_ma); > > bpf_mem_alloc_destroy(&htab->ma); > > @@ -782,7 +759,7 @@ static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node) > > b = __select_bucket(htab, tgt_l->hash); > > head = &b->head; > > > > - ret = htab_lock_bucket(htab, b, tgt_l->hash, &flags); > > + ret = htab_lock_bucket(b, &flags); > > if (ret) > > return false; > > > > @@ -793,7 +770,7 @@ static bool htab_lru_map_delete_node(void *arg, struct bpf_lru_node *node) > > break; > > } > > > > - htab_unlock_bucket(htab, b, tgt_l->hash, flags); > > + htab_unlock_bucket(b, flags); > > > > return l == tgt_l; > > } > > @@ -1107,7 +1084,7 @@ static int htab_map_update_elem(struct bpf_map *map, void *key, void *value, > > */ > > } > > > > - ret = htab_lock_bucket(htab, b, hash, &flags); > > + ret = htab_lock_bucket(b, &flags); > > if (ret) > > return ret; > > > > @@ -1152,7 +1129,7 @@ static int htab_map_update_elem(struct bpf_map *map, void *key, void *value, > > } > > ret = 0; > > err: > > - htab_unlock_bucket(htab, b, hash, flags); > > + htab_unlock_bucket(b, flags); > > return ret; > > } > > > > @@ -1198,7 +1175,7 @@ static int htab_lru_map_update_elem(struct bpf_map *map, void *key, void *value, > > copy_map_value(&htab->map, > > l_new->key + round_up(map->key_size, 8), value); > > > > - ret = htab_lock_bucket(htab, b, hash, &flags); > > + ret = htab_lock_bucket(b, &flags); > > if (ret) > > return ret; > > > > @@ -1219,7 +1196,7 @@ static int htab_lru_map_update_elem(struct bpf_map *map, void *key, void *value, > > ret = 0; > > > > err: > > - htab_unlock_bucket(htab, b, hash, flags); > > + htab_unlock_bucket(b, flags); > > > > if (ret) > > htab_lru_push_free(htab, l_new); > > @@ -1255,7 +1232,7 @@ static int __htab_percpu_map_update_elem(struct bpf_map *map, void *key, > > b = __select_bucket(htab, hash); > > head = &b->head; > > > > - ret = htab_lock_bucket(htab, b, hash, &flags); > > + ret = htab_lock_bucket(b, &flags); > > if (ret) > > return ret; > > > > @@ -1280,7 +1257,7 @@ static int __htab_percpu_map_update_elem(struct bpf_map *map, void *key, > > } > > ret = 0; > > err: > > - htab_unlock_bucket(htab, b, hash, flags); > > + htab_unlock_bucket(b, flags); > > return ret; > > } > > > > @@ -1321,7 +1298,7 @@ static int __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key, > > return -ENOMEM; > > } > > > > - ret = htab_lock_bucket(htab, b, hash, &flags); > > + ret = htab_lock_bucket(b, &flags); > > if (ret) > > return ret; > > > > @@ -1345,7 +1322,7 @@ static int __htab_lru_percpu_map_update_elem(struct bpf_map *map, void *key, > > } > > ret = 0; > > err: > > - htab_unlock_bucket(htab, b, hash, flags); > > + htab_unlock_bucket(b, flags); > > if (l_new) > > bpf_lru_push_free(&htab->lru, &l_new->lru_node); > > return ret; > > @@ -1384,7 +1361,7 @@ static int htab_map_delete_elem(struct bpf_map *map, void *key) > > b = __select_bucket(htab, hash); > > head = &b->head; > > > > - ret = htab_lock_bucket(htab, b, hash, &flags); > > + ret = htab_lock_bucket(b, &flags); > > if (ret) > > return ret; > > > > @@ -1397,7 +1374,7 @@ static int htab_map_delete_elem(struct bpf_map *map, void *key) > > ret = -ENOENT; > > } > > > > - htab_unlock_bucket(htab, b, hash, flags); > > + htab_unlock_bucket(b, flags); > > return ret; > > } > > > > @@ -1420,7 +1397,7 @@ static int htab_lru_map_delete_elem(struct bpf_map *map, void *key) > > b = __select_bucket(htab, hash); > > head = &b->head; > > > > - ret = htab_lock_bucket(htab, b, hash, &flags); > > + ret = htab_lock_bucket(b, &flags); > > if (ret) > > return ret; > > > > @@ -1431,7 +1408,7 @@ static int htab_lru_map_delete_elem(struct bpf_map *map, void *key) > > else > > ret = -ENOENT; > > > > - htab_unlock_bucket(htab, b, hash, flags); > > + htab_unlock_bucket(b, flags); > > if (l) > > htab_lru_push_free(htab, l); > > return ret; > > @@ -1494,7 +1471,6 @@ static void htab_map_free_timers(struct bpf_map *map) > > static void htab_map_free(struct bpf_map *map) > > { > > struct bpf_htab *htab = container_of(map, struct bpf_htab, map); > > - int i; > > > > /* bpf_free_used_maps() or close(map_fd) will trigger this map_free callback. > > * bpf_free_used_maps() is called after bpf prog is no longer executing. > > @@ -1517,10 +1493,10 @@ static void htab_map_free(struct bpf_map *map) > > bpf_map_area_free(htab->buckets); > > bpf_mem_alloc_destroy(&htab->pcpu_ma); > > bpf_mem_alloc_destroy(&htab->ma); > > + > > if (htab->use_percpu_counter) > > percpu_counter_destroy(&htab->pcount); > > - for (i = 0; i < HASHTAB_MAP_LOCK_COUNT; i++) > > - free_percpu(htab->map_locked[i]); > > + > > lockdep_unregister_key(&htab->lockdep_key); > > bpf_map_area_free(htab); > > } > > @@ -1564,7 +1540,7 @@ static int __htab_map_lookup_and_delete_elem(struct bpf_map *map, void *key, > > b = __select_bucket(htab, hash); > > head = &b->head; > > > > - ret = htab_lock_bucket(htab, b, hash, &bflags); > > + ret = htab_lock_bucket(b, &bflags); > > if (ret) > > return ret; > > > > @@ -1602,7 +1578,7 @@ static int __htab_map_lookup_and_delete_elem(struct bpf_map *map, void *key, > > free_htab_elem(htab, l); > > } > > > > - htab_unlock_bucket(htab, b, hash, bflags); > > + htab_unlock_bucket(b, bflags); > > > > if (is_lru_map && l) > > htab_lru_push_free(htab, l); > > @@ -1720,7 +1696,7 @@ __htab_map_lookup_and_delete_batch(struct bpf_map *map, > > head = &b->head; > > /* do not grab the lock unless need it (bucket_cnt > 0). */ > > if (locked) { > > - ret = htab_lock_bucket(htab, b, batch, &flags); > > + ret = htab_lock_bucket(b, &flags); > > if (ret) { > > rcu_read_unlock(); > > bpf_enable_instrumentation(); > > @@ -1743,7 +1719,7 @@ __htab_map_lookup_and_delete_batch(struct bpf_map *map, > > /* Note that since bucket_cnt > 0 here, it is implicit > > * that the locked was grabbed, so release it. > > */ > > - htab_unlock_bucket(htab, b, batch, flags); > > + htab_unlock_bucket(b, flags); > > rcu_read_unlock(); > > bpf_enable_instrumentation(); > > goto after_loop; > > @@ -1754,7 +1730,7 @@ __htab_map_lookup_and_delete_batch(struct bpf_map *map, > > /* Note that since bucket_cnt > 0 here, it is implicit > > * that the locked was grabbed, so release it. > > */ > > - htab_unlock_bucket(htab, b, batch, flags); > > + htab_unlock_bucket(b, flags); > > rcu_read_unlock(); > > bpf_enable_instrumentation(); > > kvfree(keys); > > @@ -1815,7 +1791,7 @@ __htab_map_lookup_and_delete_batch(struct bpf_map *map, > > dst_val += value_size; > > } > > > > - htab_unlock_bucket(htab, b, batch, flags); > > + htab_unlock_bucket(b, flags); > > locked = false; > > > > while (node_to_free) { > -- Best regards, Tonghao